You have had at least four partners since July with oral sex on all and, on at least one occasion had brief unprotected rectal intercourse with a partner of unknown HIV status. At last two of your recent partners are known to you to have HIV. So where do things stand:
1. No, the timing of testing for gonorrhea and chlamydia was fine. Syphilis would take, on average, 3 weeks for your test to become positive. It is rare however. Herpes -lesions typically appear in a week to 10 days. Odds are, at this time, you do not have an STD.
2. If this sort of behavior persists, you should be tested regularly and, at the rate of partner change you mention, probably as often as every six months. A more important question is, do you really want to put yourself at risk? While your risk is relatively low for any single expsoure, the facts are, partners met over the net are more likely on a statistical basis to be HIV infected than partners met in other social settings. Secondly, the risk of oral sex is low but with enough exposures, you can shift those odds. More exposures, even if they are low risk, can lead to infection if there are enough of them. As for unprotected rectal sex, the odds of becoming infected are 100 times higher than for oral sex. I urge you to think long and hard about safe sex. Why push your luck?
EWH
Thank you so much for your feedback and response. I am extremely appreciative that you took the time. Due to the fact that I had exceeded my 2,000 character limit, I was unable to indicate that I have definitely come to the full conclusion that these casual occurences are not worth it, regardless of how vulnerable and hurt I might feel as the result of a broken relationship. Since I do no like being tested, this behavior will not persist. Naturally, you are absolutely correct, pushing my luck is not the answer!